[Coco] Update: os9gen on 128k coco3, rs323 pack

[Steven Hirsch]

On Sun, 15 Feb 2009, Gene Heskett wrote:

> On Sunday 15 February 2009, Steven Hirsch wrote:
>> On Sun, 15 Feb 2009, Michael Furman wrote:
>>> I tried using the rs232 pak ROM and it seems to hang occasionally.
>>
>> There's an obscure problem with interrupt handling that might be behind
>> the hangs.  I have no personal experience with it, but it's written up in
>> "Tandy's Little Wonder" (Farna Systems?).  IIRC, interrupts are not
>> properly shared between the cartridge slot and the GIME with the end
>> result being that SIO interrupts can be lost.  Again, just speculation
>> that this is the issue!
>>
> There is about a 100/1 chance that is correct.  The fix is to remove three of
> the 4 pullup r's tied to each card socket pin 8, and then jumper all sockets
> pin 8's together.  This allows the IRQ to get through to the coco and be
> serviced regardless of where the slot switch is, or what slot was last
> selected by the software.

Gene,

I don't think he's using an MPI.  The problem I'm referring to is internal 
to the computer and has to do with how the cart interrupt is routed to the 
CPU.


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